Taoiseach Enda Kenny has said he hopes all sides involved in the project can put the difficulties of the past behind them.

The row began after Mr Wallace said he was not being properly consulted. It also emerged that Ms Ryan was appointed without public consultation.

Asked whether the entire board should resign, Mr O'Connor said: "Nobody is denying that we are in a very challenging situation, but this is the first time we have had a national city of culture project. This is the first time for everybody."

"There's no tool kit sitting on a shelf that we were able to pull down. Everybody's had to make their way through this."

Mr O'Connor also said he was "very concerned" at suggestions that Ms Ryan's phone may have been hacked.

A report in the Irish Independent suggests Ms Ryan believes her phone messages may have been intercepted.

Mr O'Connor said he understood Ms Ryan has grave concerns and will be taking the matter up with gardaí.

"I'd be very concerned at anything illegal happening to any colleague. That would be a criminal matter and it should be dealt with accordingly," he said.

Limerick TD Willie O'Dea earlier called on both sides in the dispute to "step back" from their entrenched positions.

Speaking on the same programme, Mr O'Dea called on Minister for Arts, Heritage and the Gaeltacht Jimmy Deenihan to intervene if those involved could not "get their act together".